Pirates on the Chennai coast

While the countdown for the return of the brown-headed and black-headed gulls to their breeding grounds has begun, here is a late-season display of kleptoparasitism by a brown-headed gull at the Muttukadu-Covelong backwaters. And this “event” took place on May Day, dedicated to those earning their livelihood by the sweat of their brow

The day was cradled in the crook of two united arms, one a late afternoon and the other an early evening. Encouraged by the improving weather, an “audience” had gathered on the bridge over the Muttukadu-Covelong backwaters. Those with eyes to see could witness a quirk of nature.

A brown-headed gull entered the scene. The only gull in sight, it left its intentions unclouded. It was set to go after any cormorant that got lucky. For that matter, any bird with a catch. This intention was as transparent as Muttukadu-Covelong backwaters made pellucid by a still fiercely-probing sun. A clutch of little egrets were out fishing in the backwaters, and the brown-headed gull would not discriminate against them. It would take their food too, by force, if it could. Here is an exposition of kleptoparasitism, ironically on a day dedicated to those earning their livelihood by the sweat of their brow, May Day.

A corner of the Muttukadu-Covelong backwaters was in a state of tizzy, boats having stirred up the waters. The boats moving east resolutely towards a groyne as if to touch it in a game of kho-kho, were orchestrating a mid-week revelry for May Day holidayers. This sight is common on weekends but not on a Wednesday.

Cormorants are known to wade into “disturbed” waters. Usually, they are uninvited partners in a rafting exercise by spot-billed pelicans. They dip their webbed feet into disturbed shoals of fish, “beaking up” some of them. This evening, there were a couple of spot-billed pelicans and cormorants were bobbing around them. But the cormorants were actually concentrated in the wasters “disturbed” by the boats. In characteristic style, little egrets were fishing in the edges of the waterway. A few little egrets were more enterprising: they were in flight, skimming the surface of the waters trying to take their food from the centre of the “cistern”.

The brown-headed gull was hovering over cormorants that held up their trophy, a fish clutched in their beaks. A couple of little egrets also felt the hot breath of the brown-headed gull on their tails. On a couple of occasions, this writer could see a transfer (a forced transfer) of the fish from one beak to another. Of course, the receiving beak every time was the brown-headed gull’s.

Kleptoparasitism is an inter-special phenomenon, being pronounced in some species of the animal kingdom. A species is known as a kleptoparasite by the deliberation with which it goes after another’s food. Gulls exhibit this deliberation much like the enthusiasm with which pirates go after resourceful ships. On the Chennai coast, during the migratory season, the brown-headed and black-headed gulls are representatives that sell this skill through a door-to-door demonstration of it. In Pulicat, just off the fish house, as fishermen bring in their catch and leave them unguarded for a moment on the platform, these gulls would dip their beaks into the kitty.

That sight is not so common at Muttukadu-Covelong. However, when avian fishers turn up in plentiful numbers in these parts, these gulls would try their trick on these birds, and often with an impressive strike rate.